1. Field of the Invention
This invention relates to a coherent array of surgical staples formed when the staples are bonded together by a biodegradable, absorbable plastic.
2. Description of the Prior Art
Surgical stapling instruments which are actuated repetitively to discharge and form, in sequence, a series of surgical staples one at a time are well known in the art. One type of surgical stapler is used for ligating blood vessels and the like during surgical operations, whereas another type is used for joining together a variety of tissues within the body such as bronchia, intestines, blood vessels and so forth. Still another type is used for joining disunited skin or fascia. Among these types of staplers are those which have in common the method of feeding staples in a stacked array of individual staples, one staple pushing the other.
In some prior art surgical staplers, the stacked array, comprised of individual surgical staples, is mounted in a cartridge for insertion into an instrument. In other prior art staplers, the array of individual surgical staples is mounted within a housing contained in the instrument itself.
Examples of prior art surgical staplers of the type described can be found in U.S. Pat. Nos. 2,853,074, 3,874,384, 3,079,608, 3,225,996, 3,489,330, 3,604,561 and 3,873,016.
In all of the surgical staplers which make use of a stacked staple array, the first staple in the array is pushed out of the cartridge or instrument by a driver which is moved in response to the actuation of the instrument; the staple is clinched against an anvil as the instrument is actuated. After application of the staple, when the instrument is returned to its normal starting condition, a pusher moves the series of staples forward so that the next successive staple in the array will be in position to be applied when the instrument is again actuated.
Except for skin staplers which use the relatively larger diameter wires of 0.020 inch or greater, none of the other surgical staplers have attained significant commercial use. At least one of the reasons why these staplers have not come into common use is that the above-described method of staple-feeding is not entirely reliable. Frequently, surgical staplers are required to feed staples made from very small diameter wire. One prior art stapler contemplates the use of wires having diameters as small as 0.006 inches. Staples made from such small wire must be fed in closely fitted guide grooves within the staple cartridge, or instrument, so that the manufacturing tolerances of both the preformed staple and the guide grooves become extremely critical. If the grooves are too large, the staples move sideways on one another and bind, and generally interfere with smooth feeding. Such interference leads to staple jams, which render the instrument inoperative. Because the instruments are less than reliable for the reason described above, their use has not become widespread.
There is thus a need for an improved staple array which minimizes the problem of staple jams when used in a surgical stapling instrument that relies on a stacked staple array.